The subject matter of the present application is related to the subject matter of co-pending application entitled xe2x80x9cDynamic. Isolating Mount for Processor Packages,xe2x80x9d incorporated herein by reference.
Not applicable.
1. Field of the Invention
The present invention generally relates to the use of vibration isolation in mounting an electrical component on a circuit board. More particularly, the present invention relates to a tunable vibration damper for a microprocessor package.
2. Background of the Invention
For many decades, circuit boards, such as those used in computers, have been manufactured by attaching electrical components to the board. In some cases, the components are soldered directly to the board. Although generally satisfactory, soldering a component directly to the board makes it difficult and costly to change that component should it be desired or necessary to replace one component with another. A microprocessor, for example, may have hundreds of connections that, should the processor fail, must be desoldered. A new processor, with its hundred of connections must then be attached to the board. Further, this process must occur without damaging the other components mounted on the circuit board. Even if the processor has not failed, it still might be desired to replace it, for example, a new and improved version of the processor is made available.
For these and other reasons, xe2x80x9cinterposerxe2x80x9d sockets have become available. Although defined in various ways, an interposer socket is a socket to which a chip (i.e., a microprocessor) is mated. The socket is then mated to the circuit board or to a socket soldered to the circuit board. Advantageously, an interposer docket does not require solder either to be mated to the board (or other socket) or to the electrical component mounted on it. Instead, a lever or other mechanism is engaged to hold the interposer socket to the circuit board.
As technology has progressed, some chips (i.e., microprocessors) have become more powerful and accordingly consume more electrical power. This increase in power usage causes the chips to become hotter and larger heat sinks are required to dissipate the increased thermal load. Mounting a large chip with a heat sink in an interposer socket may be problematic in the face of shock/vibration loads.
For example, motion caused by a fan, opening and closing cabinet doors in a rack of computers, seismic activity, and vibration induced by adjacent equipment may cause interposer sockets to fail and become intermittent. Obviously, this failure may cause the electrical component contained in the interposer to cease functioning as intended.
For successful operation and prevention of premature socket failure, the source of the vibration should be eliminated. If this is impossible or difficult, then a vibration isolation device should be used at or near the socket to minimize the potential for the socket to fail.
The present invention relates to a method and apparatus that minimizes shock/vibrational motion in interposer sockets. The ability to control shock/vibration can ensure successful operation and substantially increase socket lifetime.
In accordance with a preferred embodiment of the present invention, a device for maintaining a heat sink in a desired relationship with a mounting base while limiting the transmission of shock and vibrational motion to and from the heat sink includes a fastener extending from the mounting base, a spring compressed between the fastener and the heat sink, and a damper compressed between the fastener and the heat sink wherein the fastener maintains the spring and the damper in a compressed state such that the spring and the damper bear on said heat sink.
In accordance with another preferred embodiment of the present invention, a method for limiting shock/vibrational motion of a microprocessor includes placing a damping material in parallel with a clamping spring, wherein the damping material is in the form of a sleeve that surrounds the clamping spring.
In accordance with yet another preferred embodiment of the present invention, a method for limiting shock/vibrational motion of a microprocessor comprising placing a damping material in series with a clamping spring, wherein the damping material is in the form of a viscous liquid inside the capscrew, similar to a shock absorber.
These and other aspects of the present invention will become apparent upon studying the following detailed description, figures and claims.